compiler.h

// Copyright 2019 The Pigweed Authors
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.
//
// Preprocessor macros that wrap compiler-specific features.
// This file is used by both C++ and C code.
#pragma once
 
// TODO: b/234877280 - compiler.h should be refactored out of pw_preprocessor as
// the scope is outside of the module. Perhaps it should be split up and placed
// under pw_compiler, e.g. pw_compiler/attributes.h & pw_compiler/builtins.h.
 
#include "pw_polyfill/static_assert.h"
 
 
 
#define PW_PACKED(declaration) declaration __attribute__((packed))
 
#define PW_USED __attribute__((used))
 
#define PW_NO_PROLOGUE __attribute__((naked))
 
#define PW_PRINTF_FORMAT(format_index, parameter_index) \
  __attribute__((format(_PW_PRINTF_FORMAT_TYPE, format_index, parameter_index)))
 
#ifdef __USE_MINGW_ANSI_STDIO
#define _PW_PRINTF_FORMAT_TYPE gnu_printf
#else
#define _PW_PRINTF_FORMAT_TYPE printf
#endif  // __USE_MINGW_ANSI_STDIO
 
#ifdef __APPLE__
#define PW_PLACE_IN_SECTION(name) __attribute__((section("__DATA," name)))
#else
#define PW_PLACE_IN_SECTION(name) __attribute__((section(name)))
#endif  // __APPLE__
 
#ifdef __APPLE__
#define PW_KEEP_IN_SECTION(name) __attribute__((section("__DATA," name), used))
#else
#define PW_KEEP_IN_SECTION(name) __attribute__((section(name), used))
#endif  // __APPLE__
 
#define PW_NO_RETURN __attribute__((noreturn))
 
#define PW_NO_INLINE __attribute__((noinline))
 
#define PW_UNREACHABLE __builtin_unreachable()
 
#ifdef __clang__
#define PW_NO_SANITIZE(check) __attribute__((no_sanitize(check)))
#else
#define PW_NO_SANITIZE(check)
#endif  // __clang__
 
#ifdef __has_attribute
#define PW_HAVE_ATTRIBUTE(x) __has_attribute(x)
#else
#define PW_HAVE_ATTRIBUTE(x) 0
#endif  // __has_attribute
 
#if defined(__cplusplus) && defined(__has_cpp_attribute)
#define PW_HAVE_CPP_ATTRIBUTE(x) __has_cpp_attribute(x)
#else
#define PW_HAVE_CPP_ATTRIBUTE(x) 0
#endif  // defined(__cplusplus) && defined(__has_cpp_attribute)
 
#define _PW_REQUIRE_SEMICOLON \
  static_assert(1, "This macro must be terminated with a semicolon")
 
#define PW_MODIFY_DIAGNOSTICS_PUSH() \
  _Pragma("GCC diagnostic push") _PW_REQUIRE_SEMICOLON
 
#define PW_MODIFY_DIAGNOSTICS_POP() \
  _Pragma("GCC diagnostic pop") _PW_REQUIRE_SEMICOLON
 
#define PW_MODIFY_DIAGNOSTIC(kind, option) \
  PW_PRAGMA(GCC diagnostic kind option) _PW_REQUIRE_SEMICOLON
 
#ifdef __clang__
#define PW_MODIFY_DIAGNOSTIC_GCC(kind, option) _PW_REQUIRE_SEMICOLON
#else
#define PW_MODIFY_DIAGNOSTIC_GCC(kind, option) \
  PW_MODIFY_DIAGNOSTIC(kind, option)
#endif  // __clang__
 
#ifdef __clang__
#define PW_MODIFY_DIAGNOSTIC_CLANG(kind, option) \
  PW_MODIFY_DIAGNOSTIC(kind, option)
#else
#define PW_MODIFY_DIAGNOSTIC_CLANG(kind, option) _PW_REQUIRE_SEMICOLON
#endif  // __clang__
 
#define PW_PRAGMA(contents) _Pragma(#contents)
 
#define PW_WEAK __attribute__((weak))
 
#define PW_ALIAS(aliased_to) __attribute__((weak, alias(#aliased_to)))
 
#if PW_HAVE_CPP_ATTRIBUTE(clang::lifetimebound)
#define PW_ATTRIBUTE_LIFETIME_BOUND [[clang::lifetimebound]]
#elif PW_HAVE_ATTRIBUTE(lifetimebound)
#define PW_ATTRIBUTE_LIFETIME_BOUND __attribute__((lifetimebound))
#else
#define PW_ATTRIBUTE_LIFETIME_BOUND
#endif  // PW_ATTRIBUTE_LIFETIME_BOUND
 
#define PW_ADD_OVERFLOW(a, b, out) __builtin_add_overflow(a, b, out)
 
#define PW_SUB_OVERFLOW(a, b, out) __builtin_sub_overflow(a, b, out)
 
#define PW_MUL_OVERFLOW(a, b, out) __builtin_mul_overflow(a, b, out)
 
#if (defined(__clang_major__) && __clang_major__ < 9) || \
    (defined(__GNUC__) && __GNUC__ < 12)
#define PW_VA_OPT_SUPPORTED() 0  // Don't bother checking on old compilers.
#else
#define PW_VA_OPT_SUPPORTED() _PW_VA_OPT_SUPPORTED()
 
#define _PW_VA_OPT_SUPPORTED(...) _PW_VA_OPT_SUPPORTED_##__VA_OPT__()
#define _PW_VA_OPT_SUPPORTED_ 1
#define _PW_VA_OPT_SUPPORTED___VA_OPT__() 0
 
#endif  // __clang_major__ < 9 || __GNUC__ < 12
 
#if PW_HAVE_CPP_ATTRIBUTE(no_unique_address)
#define PW_NO_UNIQUE_ADDRESS [[no_unique_address]]
#else
#define PW_NO_UNIQUE_ADDRESS
#endif  // PW_NO_UNIQUE_ADDRESS